CVE-2026-80104, a 9.8-severity path-traversal and arbitrary-file-write flaw in the AI application framework DB-GPT, names v0.8.1 as the version that fixes it. That is accurate and dangerously incomplete: v0.8.1 is the only released version that contains the fix.
What we checked, and how
The guard is a function called _validate_upload_filename, added on 21 May 2026, which rejects null bytes, absolute POSIX and Windows paths, and any filename containing more than one path component. We fetched the relevant source file at the v0.8.1 tag and at the v0.8.2 tag and compared them. At v0.8.1 the function is present. At v0.8.2 — released this morning — it is gone, and the handler reads filename = file.filename directly before joining it to the upload directory and writing the bytes. No canonicalisation, no containment check.
How a fix disappears
The loss traces to a feature branch cut before the fix landed. When that branch was merged in June, its version of the file — which predates 21 May — replaced the patched one. Nothing was reverted deliberately; the guard was simply overwritten by an older copy of the same function, which is why no changelog entry records it.
What the common framing gets wrong
An advisory's "patched version" field is universally read as "this version and everything after it." That is what scanners assume, what dependency bots act on, and what an operator concludes. Here the field is a point, not a floor: a team reading the advisory and upgrading to the newest release does exactly the wrong thing and lands on vulnerable code while believing itself remediated. The advisory is not wrong — it is being read with an assumption that does not hold.
The authentication makes it worse
The upload route's sole dependency is a function whose source is commented "Mock User Info" and which returns a user object with role="admin" whether or not any user header is supplied. Both branches are admin. That is the current released code, not an abandoned tag — so the file-write primitive is reachable without authenticating.